Cassini has captured an image of a truly huge storm on Saturn. Click on the image below to see the full image.
The image below was taken on January 11, 2011 by the space probe Cassini, in orbit around Saturn. First we see the southern polar regions of the moon Rhea, 949 miles in diameter. Beyond is the moon Dione, 698 miles across, appearing to sit on the rings of Saturn.
As far as I am concerned, this image, as well as almost every other image from Cassini, proves that any hotel built in orbit around Saturn is unquestionably going to be one of the hottest tourist spots in the solar system.
Cassini has directly sampled the plumes from Enceladus and discovered a salty ocean-like spray.
The new paper analyzes three Enceladus flybys in 2008 and 2009 with the same instrument, focusing on the composition of freshly ejected plume grains. The icy particles hit the detector target at speeds between 15,000 and 39,000 mph (23,000 and 63,000 kilometers per hour), vaporizing instantly. Electrical fields inside the cosmic dust analyzer separated the various constituents of the impact cloud.
The data suggest a layer of water between the moon’s rocky core and its icy mantle, possibly as deep as about 50 miles (80 kilometers) beneath the surface. As this water washes against the rocks, it dissolves salt compounds and rises through fractures in the overlying ice to form reserves nearer the surface. If the outermost layer cracks open, the decrease in pressure from these reserves to space causes a plume to shoot out. Roughly 400 pounds (200 kilograms) of water vapor is lost every second in the plumes, with smaller amounts being lost as ice grains. The team calculates the water reserves must have large evaporating surfaces, or they would freeze easily and stop the plumes.
Evidence mounts for liquid water on Enceladus.
Scientists have found evidence that a subsurface ocean of water and ammonia exists within Saturn’s moon Titan.
Saturn and Enceladus linked by electricity.
The ripples in the rings of Saturn and Jupiter were caused by comet impacts decades ago.
The spring rains (of methane) have arrived on Titan.
The tiger stripe fissures on Saturn’s moon Enceladus have turned out to be far hotter than predicted.
The sponge-like Saturn moon. Key quote:
Hyperion measures about 250kms across; it rotates chaotically and has a density so low that it might house a vast system of caverns inside.
A fizzy ocean on Enceladus? Key quote:
[Scientists believe] that gasses dissolved in water deep below the surface [of Enceladus] form bubbles. Since the density of the resulting “sparkling water” is less than that of the ice, the liquid ascends quickly up through the ice to the surface. “Most of the water spreads out sideways and ‘warms’ a thin surface ice lid, which is about 300 feet thick,” explains Matson. “But some of it collects in subsurface chambers, builds up pressure, and then blasts out through small holes in the ground, like soda spewing out of that can you opened.”
A vast storm rages across the face of Saturn.
A cyclone on Saturn has now lasted more than five years, since scientists started tracking it closely in 2004 with the arrival of Cassini in orbit around Saturn.
Scientists have used data from Cassini to identify what they think are ice volcanoes on Titan. The two volcanoes, each about 3000 feet high, are located near the equator and appear to resemble the volcanoes on Earth, with a central crater on top of cone-like peak and finger-like flows coming down the sides from the crater. The lava here, however, is not molten rock, but water.
Scientists have created a computer simulation describing the violent origin of Saturn’s rings, with moons being stripped of their ice as they death spiral into Saturn.
Note that this is only a theory, illustrated by a computer model. Though it is fascinating however!
Cassini pinpoints the hot spots in the cracks on Enceladus.
Saturn moon has a thin oxygen and carbon dioxide atmosphere. Key quote:
“The major implication of this finding at Rhea is that oxygen atmospheres at icy moons, until now only detected at Europa and Ganymede, may in fact be commonplace around those irradiated icy moons throughout the universe with sufficient mass to hold an atmosphere,” said study leader Ben Teolis of the Southwest Research Institute in San Antonio, Texas.
Cassini back in operation.
Engineers expect to get Cassini, which went into safe mode on November 2, back in operation by next week.
Cassini went into safe mode on Tuesday, November 2nd. At the moment engineers expect it to take at least another week to get the spacecraft back to normal.
Steve Squyres of Cornell University and the project scientist of the Mars rovers Spirit and Opportunity spoke today at an astrobiology symposium in Arlington, Virginia. He described several spectacular planetary missions that might be flown in the coming decade. All are being considered. None have yet been chosen or funded.
Squyres is the co-chair of a committee of the National Science Foundation that is right now putting together a decadal survey for outlining unmanned planetary research for the next decade. This survey is expected to be released in March, which is when we will find out which of the above missions the planetary science community prefers.
Big news! In a simulation of the upper atmosphere of Titan at about 600 miles altitude, scientists have discovered the basic ingredients of life are quickly synthesized when exposed to the kind of hard radiation found there. Key quote from the press release, issued today at the 42nd meeting of the AAS Division for Planetary Sciences:
The molecules discovered include the five nucleotide bases used by life on Earth (cytosine, adenine, thymine, guanine and uracil) and the two smallest amino acids, glycine and alanine.
For those who don’t remember their high school biology, these nucleotides are the building blocks of DNA.
The abstract of the scientist’s work can be found here.
What the scientists did was recreate the basic ingredients of Titan’s upper atmosphere, comprised of nitrogen, methane and carbon monoxide. Cassini data has shown that within this atmosphere are very large molecules, as yet unidentified.
The scientists then bathed their recreation in the kind of intense radiation expected at that altitude, and amazingly produced the complex organic molecules that are basic to life. Moreover, the experiment was the first to produce these complex molecules without the presence of water, something that scientists have previously thought was required. These results suggest that in addition to forming in the oceans, life could also form in the upper atmospheres of planets.
This result also suggests strongly that it is incredibly easy to produce the basic building blocks of life, almost anywhere in the universe where organic molecules are present.
The plumes that come out of the tiger stripe cracks on Saturn’s moon Enceladus may be carbonated!
The Cassini image below, released today at the 42nd meeting of the AAS Division for Planetary Sciences, shows light reflecting off a lake on Titan’s northern hemisphere. According to the scientists who took the image, this is the first definitive confirmation of the presence of liquid in those lakes.
The Cassini spacecraft orbiting Saturn continues to send back a wealth of data, and some gob-smacking wonderful images. Below are two of the more recent examples. The first is not a computer-generated graphic: it shows the small moon Helene (21 miles across) during a fly-by on March 3, 2010, with Saturn’s atmosphere providing the background. The second captures Saturn’s two largest moons, with the smaller Rhea crossing in front of the larger Titan.
Spring on Titan brings sunshine and patchy clouds.
This breath-taking image of Saturn and its rings was taken by Cassini on July 19, 2009 and posted on the Cassini image gallery on August 27, 2010.
This stunning image of Saturn, taken by Cassini on June 24, 2010, shows the ring’s widening shadow across the planet. As the planet orbits the Sun the tilt of its rings relative to the Sun changes with time. In August 2009 the tilt was essentially zero, so that the shadow was very narrow. Since then the tilt has been increasing, as has the width of the shadow.
Scientists are beginning to unravel the wind patterns on Titan.
